• Title, Summary, Keyword: Cellulose

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X-ray and Electron Diffraction Study of Cellulose Crystal Structures (X선 및 전자선회절법에 의한 천연셀룰로오스의 결정구조 해석)

  • Kim, Nam-Hun
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.3
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    • pp.72-79
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    • 1996
  • Cellulose I에서 Cellulose II로의 결정변태기구를 X선 및 전자선 회절법과 현미경적 방법을 이용하여 구명하였다. X선 회절 결과, Na-cellulose I을 고온에서 수세할 경우 Cellulose I과 Cellulose II의 혼합형 회절도가, 저온에서 수세할 경우 Na-cellulose IV의 회절도가 얻어졌다. 전자선회절 결과, 고온수세의 시료는 Cellulose I과 Cellulose II의 혼합형이 저온수세의 시료는 Cellulose II의 회절도가 얻어졌다. 또한 고온수세 시료의 전자선회절도로부터 섬유벽의 내측부가 외측부보다 재생 Cellulose I의 양이 많은 것이 확인되었다. 따라서 알칼리 팽윤시 섬유벽내에는 불완전한 팽윤이 발생하는데 그 정도는 내측부가 더욱 심한 것으로 생각된다. 이때 형성되는 불완전한 Na-cellulose I 은 고온 수세의 경우는 탈수에 의해 Cellulose I로, 저온수세의 경우는 수화에 의해 Cellulose II로 변태되지만 완전히 팽윤된 Na-cellulose I은 Cellulose I로 재생될 수 없는 것으로 생각된다. 현미경적 실험결과, mercerization과정에서 cellulose 분자쇄의 packing이나 conformation의 변화와 관련하여 microfibril 의 흐트러짐은 발생하지 않는 것으로 생각되었다.

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Transcrystallinity in iPP/cellulose allomorphs and PBS/cellulose allomorphs (iPP/cellulose allomorph와 PBS/cellulose allomorph에서의 Transcrystallinity 현상)

  • 조철호;이영목;임승순
    • Textile Science and Engineering
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    • v.36 no.1
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    • pp.34-42
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    • 1999
  • Transcrystalline phenomenon was investigated in iPP/cellulose and PBS/cellulose systems. Cellulose allomorphs were prepared and the morphology was investgated at the interface of iPP/cellulose allomorphs and PBS/cellulose allomorphs by optical micrography. The cellulose fiber which had crystalline structure of cellulose II showed nucleating ability to iPP matrix. This observation is different from other works that no transcrystallinity was induced on Fortisan, other regenerated cellulose fiber and mecerized cellulose fiber. Cellulose allomorphs, also, showed nucleating ability to iPP and PBS. Nucleating ability of cellulose I, $III_{I}$, or $IV_{I}$ was higher than that of cellulose II, $III_{II}$, or $IV_{II}$. With increase in the isothermal crystallization temperature, nucleating ability of cellulose and growth rate of transcrystalline layer were decreased.

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Formation Conditions of Na-cellulose II with Three Fold Helix (3회나선축을 갖는 Na-cellulose II의 형성조건에 관한 고찰)

  • Kim, Nam-Hun;Lee, Myoung-Ku
    • Journal of the Korean Wood Science and Technology
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    • v.27 no.1
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    • pp.18-23
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    • 1999
  • The formation conditions of Na-cellulose II with three fold helix were investigated by an x-ray diffraction method. Na-cellulose II was formed through Na-cellulose I. It seems that the concentration of sodium hydroxide in Na-cellulose II is higher than both those of Na-cellulose I and Na-cellulose III. Na-cellulose II was formed well by different rinsing and drying methods even though the sample treatment was carried out in very short periods of time. Metal-complexed Na-cellulose swollen in the mixture of $Cu(OH)_2$ and sodium hydroxide is stable in wet state, and changed to a different polymorph by drying.

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Studies on the Synthesis of Cellulose Nitrite and Its Application (II) -The regeneration of Cellulose Nitrite to cellulose and the Blending of Cellulose Derivatives with PAN- (셀룰로오스 나이트라이트의 합성과 그의 응용(II) -아질산 셀룰로오스의 셀룰로오스에의 재생 및 셀룰로오스 유도체와 PAN과의 블랜딩-)

  • Go, Seok-Won;Hwang, Hyeon-Suk;Kim, Yeong-Ho
    • Textile Science and Engineering
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    • v.20 no.3
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    • pp.28-36
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    • 1983
  • The effects of the reaction conditions in nitrosation of cellulose and the regeneration conditions of cellulose nitrite to cellulose on the molecular weight of regenerated cellulose, and the blending of cellulose nitrite or cellulose sulfate with PAN were investigated. The results are as follows. The molecular weight of regenerated cellulose is influenced by nitrosation temperature, nitrosation time and the alkalinity of regenerating liquor. X-ray diffractogram shows that the regenerated cellulose has cellulose II structure. Polyacrylonitrile is miscible with cellulose sulfate to a considerable extent, and the film of their blend is so outstanding in anti-static property that it is considered to be able to produce anti-static polyacrylic fiber.

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Recycling of Waste Cellulose Biomass - I. Synthesis of Cellulose Acetate and Mehtylcellulose from Waste Cellulose - (폐 cellulose계 biomass 자원의 재활용 - I. 목면 폐기물로부터 cellulose acetate 및 methyl cellulose 합성 -)

  • 이성구;최길영;김수진;정우영;조순채;이종문
    • Textile Coloration and Finishing
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    • v.5 no.3
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    • pp.221-228
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    • 1993
  • Cellulose acetate and methyl cellulose were synthesized from waste cellulose in order to make waste knit on value added highly. Crystal waste cellulose by oxidation using $HIO_4$ and then acetylation was decrystallized. A degee of crystallinity was measured by X-ray diffraction and the structure was identified by FT-IR spetroscopy, respectively. Cellulose acetate was prepared from the reaction of decrystallized cellulose with acetic acid, cone-$H_{2}SO_{4}$ and acetic anhydride. Also, structure identification by FT-IR and a degree of crystallinity by X-ray diffraction were performed. DS of the synthesized cellulose acetate was 2.8 and viscosity average molecular weight was 238,000. Also, methyl cellulose was synthesized by treating cellulose acetate with NaOH and iodomethane. DS of the synthesized methyl cellulose was 3.0. Glucose unit with three hydroxy groups was all substituted by methoxyl groups. It was identified by FT-IR spectroscopy. Also, the thermal properties of the synthesized methyl cellulose were examined by DSC. It shewed two shewed melting peaks at 22$0^{\circ}C$ and 24$0^{\circ}C$ in the 2nd scan. It proved that DS=3.0 of methyl cellulose was a thermotropic liquid crystal.

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A Study of Recycle of Waste Wood After Cultivating Oak Mushroom (II) - On the Structure of Cellulose Crystal Transformation of the Waste Wood - (표고버섯골목의 재활용에 관한 연구 (II) - 폐골목 세포벽 중의 셀룰로오스 결정의 변태구조 -)

  • Kim, Nam-Hun;Lee, Won-Yang
    • Journal of the Korean Wood Science and Technology
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    • v.23 no.3
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    • pp.1-7
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    • 1995
  • The crystal transformation from cellulose I to cellulose II during alkaline swelling of waste wood, which has been used for cultivating oak mushroom(Cortinellus edodes (Berk.) Ito et Imai), was investigated and compared to that of normal wood by a series of X-ray diffraction analysis. When the sapwood of cultivated wood was treated with 20% NaOH solution for 2 hours, the cellulose I can be easily transformed into Na-cellulose I than normal wood or heartwood of cultivated wood. Certainly the formation of Na-cellulose in wood is proportional to alkali swelling duration, and the formation of cultivated sapwood was faster than that of the other woods. Cellulose I in the sapwood of cultivated wood was easily transformed into cellulose II during mercerization, but the sapwood of normal wood and the heartwood of cultivated wood hardly converted to cellulose II. Namely, most of Na-cellulose I in normal wood can be reconverted to cellulose I in the process of washing and drying. Therefore, it can be concluded from this study that in cell wall lignin and hemicellulose can prevent the alkaline swelling of cellulose in wood and the transformation from cellulose I to cellulose II as well.

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EFFECTS OF DIETARY CELLULOSE AND PROTEIN LEVELS ON NUTRIENT UTILIZATION IN CHICKENS

  • Siri, S.;Tobioka, H.;Tasaki, I.
    • Asian-Australasian Journal of Animal Sciences
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    • v.7 no.2
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    • pp.207-212
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    • 1994
  • Effects of dietary cellulose and protein levels on nutrient utilization in chickens were investigated. Four experimental diets containing 5% (low cellulose) or 20% (high cellulose) cellulose in combination with 10% (low protein) or 20% (high protein) protein of 70 g/day were alternatively forced-fed to eight colostomized White Leghorn cockerels once a day to make $4{\times}4$ Latin-square design. The digestibilities of DM and energy decreased with the increase in cellulose level, but not affected by dietary protein level. Ether extract digestibility was higher in the high cellulose diets than in the low cellulose protein level. Ether extract digestibility was higher in the high cellulose diets than in the low cellulose diets. The digestibility of nitrogen free extract had the same trend with the digestibility of DM and energy. The digestibility of acid detergent fiber was not so much different among the diets, but the NDF digestibility was lower in the high cellulose diets than in the low cellulose diets, due to the low hemicellulose digestibility. The true digestibility of protein was influenced by both of the dietary protein and cellulose levels, and their interaction was found. The dietary protein level affected the biological value of protein but the dietary cellulose level did not, and consequently the biological value of protein in the low protein diets was lower than in the high protein diets.

Study on the Changes of Cellulose Molecular Weight and α-Cellulose Content by the Extrusion Conditions of Cellulose-NMMO Hydrate Solution (셀룰로오스-NMMO 수화물 용액의 압출가공 조건에 따른 셀룰로오스 분자량과 알파 셀룰로오스 함량 변화에 대한 연구)

  • Kim, Dong-Bok
    • Polymer Korea
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    • v.37 no.3
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    • pp.362-372
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    • 2013
  • During extruder processing to manufacture cellulose fiber and film using cellulose-NMMO pre-dope produced by a new method, it seems to occur the changes of molecular weight and ${\alpha}$-cellulose content of cellulose upon thermal and mechanical degradation. In an extruder making cellulose solutions from the pre-dope obtained by high-speed mixer, the changes of cellulose molecular weight and ${\alpha}$-cellulose content resulted with the variations of processing temperature, concentration of cellulose, and residence time. The molecular weight and ${\alpha}$-cellulose content of cellulose decreased with decreasing cellulose concentration and increasing processing temperature. At 15% concentration and short residence time region, the change of ${\alpha}$-cellulose content was so high due to high-shear with an increase in temperature. From these processing conditions, the variations of ${\alpha}$-cellulose content and molecular weight showed different behaviors, and these processing conditions for making cellulose solution were found to be important factors.

Characterization and Isolation of Bacteria Producing Cellulose (Cellulose 생합성 세균의 분리 및 특성)

  • Lee, Seung-Jin;Yoo, Ju-Soon;Chung, Soo-Yeol;Choi, Yong-Lark
    • Applied Biological Chemistry
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    • v.40 no.2
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    • pp.101-106
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    • 1997
  • A screening was performed to isolate the cellulose-producing microorganisms from vinegar in Korea. The isolated strain was identified as Acetobacter sp. with respect to physiological and biochemical characteristics and designated as Acetobacter CBI-2. Cellulose production of Acetobacter CBI-2 was equal with the well known cellulose-producing bacteria, A. xylinum. The result of separation on thin layer chromatography(TLC) was consistent with the degradation product of native cellulose. The presence of genes required for the cellulose biosynthesis in Acetobacter CBI-2 was confirmed by Southern hybridization.

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Modification of PAN with Cellulose Sulfate (황산 셀룰로오스에 의한 PAN의 개질)

  • No, Mu-Hak;Kim, Yeong-Ho;Go, Seok-Won
    • Textile Science and Engineering
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    • v.24 no.1
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    • pp.35-42
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    • 1987
  • Cellulose was solvated in DMF by the addition of dinitogen tetroxide, which trans formed cellulose into cellulose nitrite. Cellulose sulfate was synthesized with the reaction of the cellulose nitrite with the DMF-SO3 complex. The D.S. of cellulose sulfate could be controlled by the amount of the DMF-SO3 complex used. The blending of cellulose sulfate with PAN was investigated. The results of dynamic mechanical measurement showed that the Tg of PAN/cellulose sulfate blend shifted to higher temperature compared with that of PAN, which suggested that there exists a compatibility between the two polymers. The static electricity, the moisture regain, and the decomposition temperature of PAN/cellulose sulfate films were measured. The frictional static electricity of the blend films was decreased rapidly with the increase of the amount of cellulose sulfate.

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